Anticipated Impacts on Veteran's Healthcare: The provision of high quality healthcare requires accurate and timely diagnosis. The National Academy of Medicine asserts that ?Improving the diagnostic process is not only possible, but also represents a moral, professional, and public health imperative.? Identifying factors influencing diagnostic accuracy is essential to improving the diagnostic process. The proposed study will identify factors associated with anxiety diagnostic errors in VHA primary care mental health integration (PCMHI) and specialty mental health (MH) settings, and addresses HSR&D priority areas Mental and Behavioral Health? and ?Health Care Systems Change? and the ORD-wide priority area ?Learning Health Care System? Project Background: VHA has little information about specific determinants of current anxiety diagnostic practices and the sociotechnical context in which diagnoses are made. Unspecified anxiety disorder is the most common anxiety-related diagnosis in VHA but is often a diagnostic error. In FY2017, 408,250 Veterans enrolled in the VHA carried an unspecified anxiety disorder diagnosis, and unspecified anxiety accounted for 70% of anxiety diagnoses in PCMHI that year. However, the majority of these diagnoses are erroneous as fewer than 3% of Veterans diagnosed with unspecified anxiety meet DSM-5 criteria for this disorder. Accurate diagnosis is foundational to evidence-based healthcare, and 77% of Veterans diagnosed with unspecified anxiety meet diagnostic criteria for a specific anxiety or trauma-related disorder (generalized anxiety disorder [GAD, 44%]; posttraumatic stress disorder [PTSD, 38%]; panic disorder, 20%; social anxiety disorder 20%). Diagnostic accuracy is critical to accessing appropriate services. Only 32% of Veterans with unspecified anxiety disorder received mental health services in the year following diagnosis, compared to Veterans diagnosed with GAD (60%), panic disorder (67%), and social anxiety disorder (88%). Thus, an erroneous diagnosis of unspecified anxiety disorder is a barrier to receipt of appropriate evidence-based care for specific disorders such as PTSD, GAD, and panic disorder. Project Objectives: The proposed, 3-year, multisite study will use mixed quantitative and qualitative methods, informed by the Safer Dx framework, to identify system-, provider-, and patient-level factors associated with anxiety diagnostic specificity in VHA PCMHI and specialty MH settings. Understanding how these factors interact in the anxiety diagnostic process is crucial to identifying point(s) in the diagnostic process at which to intervene. Project Methods: The aims of the proposed project will be achieved through three major activities that will be carried out using mixed, qualitative and quantitative, methods. Aim 1 will use administrative data from the Corporate Data Warehouse (CDW) to identify system-, provider-, and patient-level factors associated with anxiety diagnostic specificity in PCMHI and specialty MH settings. Aim 2 will consist of qualitative interviews with PCMHI and specialty MH providers to understand their perspectives on barriers and facilitators to anxiety diagnostic specificity. Aim 3 will identify barriers to anxiety diagnostic specificity in each phase of the diagnostic process outlined by the Safer Dx framework. This aim will be achieved through chart reviews and diagnostic interviews of patients diagnosed with unspecified anxiety disorder, as well as critical incident interviews with PCMHI and specialty MH providers. Next Steps: Findings from this study will position the research team to design and test a tailored intervention to facilitate mental health providers' accurate and timely diagnosis of anxiety- and trauma-related disorders for Veterans.